MacBook Air Suddenly With More Empty Space

macrumors newbie

Hi, I have a strange problem. I ran my DaisyDisk yesterday and it told me I have 4 more GB left on my Air. Today some strange things happened when I accidently let the battery run emty and then plugged Air in and turned it on. Some applications (including Byword and Fantastical) gave me message "application is damaged... download it again from App Store", Dropbox didn't want to run saying it can't establish a secure connection and spotlight was analyzing my computer for minutes. When it finished, apps were working again, but the disk is now emptier. DaisyDisk informs me I have 7 GB space left. I am kind of worried that some data corruption happened in this scary process, though right now I can't confirm it yet beside this misterious lack of 3 GB. What do you suggest, dear MacRumors people? Thank you in advance.

macrumors 68000

I suspect the problem was caused by your Mac trying to hibernate your system when the battery ran down. Your system was trying to copy the contents of your RAM to your hard disk, and it possibly failed due to the small amount of hard disk space that you have available. This may lead to file corruption. The amount of hard disk space required for hibernate can be as much as the RAM that you have on your system, sometimes slightly more.

Also your Mac may require hard disk space for virtual memory. When you reboot your system some of these caches get cleared and this is why your available hard disk space changes.

The bottom line is you need to move some stuff off your hard disk, you don't have enough free space. Ideally you should have 10% of your total capacity as free space, operate with less and you may run into issues. There is an article here that gives some advice on house cleaning your SSD.

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